Vapour Compression Cycle: Types and Numerical Analysis
- 1. Prof.R.S.KOLHE Prof. R.S. KOLHE ME (HEAT POWER) BE (MECHANICAL) WELCOME TO Heating, Ventilation, Air Conditioning and Refrigeration Engineering
- 2. Lecture No 01 Topics to be covered • Basics of HVAC • Vapour compression cycle (VCR) • Performance of VCR • Representation of VCR on P-H and T-S plane
- 3. BASICS OF HVAC • H- Heating • V- Ventilation • AC- Air-conditioning
- 4. • HEATING : Designing the system for low temperature climate ( cold climate) • VENTILATION: It is the fresh air penetrated form outside. It is a process of replacing air in conditioning space by fresh air having high indoor quality . • REFRIGERATION : It is process of removing heat from body or space so that its temperature first reduce and then maintained at a temperature less than surrounding. • AIR CONDITIONING : Air-conditioning is the process of treating air so as to control its temperature, humidity, cleanliness( air quality) and distribution to meet the requirements of the condition space.
- 5. Expectation From HVAC • Cooling or Heating to control Temperature. • Humidify or Dehumidify to control moisture content. • Filter to remove contaminants • Ventilate to supply fresh high quality air . • Circulate to regulate air motion .
- 6. Vapour Compression Cycle • Compressor • Condenser • Expansion device • Evaporator
- 7. Standard Vapour Compression Refrigeration System (VCRS) • Process 1-2: Isentropic compression of saturated vapour in compressor • Process 2-3: Isobaric heat rejection in condenser • Process 3-4: Isenthalpic expansion of saturated liquid in expansion device • Process 4-1: Isobaric heat extraction in the evaporator
- 8. Standard Vapour Compression Refrigeration System (VCRS)
- 10. Pressure – Enthalpy (P-H) Diagram
- 11. T-v diagram for the heating process of water at a) constant pressure and b) different pressure.
- 12. Pressure - Enthalpy Chart
- 13. Pressure – Enthalpy (P-H) Diagram
- 14. TEMP- ENTROPY (T-S) Diagram
- 15. PERFORMANCE OF VCC • Refrigeration Effect= h1-h4 • Refrigeration capacity = m(h1-h4) • Compressor work= (h2-h1) • COP = (RE/WC) COP =(h1-h4)/ (h2-h1)) • Heat Rejected in condenser: h2-h3
- 16. The equipment efficiency is given as EER or kW/TR ENERGY EFFICIENCY RATIO (EER) The Energy Efficiency Ratio (EER) of an HVAC cooling device is the ratio of output cooling energy (BTU/h) to input electrical energy (in watts) at a given operating point. (EER)R = kW/TR Use for large capacity equipment such as Chillers H eat ro m o val ra te in W att E n erg y In p u t in W att R kW /T R = P ow er in p u t (kW ) C ap acity (T R )
- 17. Different cases of vcc case 1: Dry saturated vapour at Entry of the compressor
- 18. CASE 2: Refrigerant is Wet at Compressor Entry • P-H Diagram • T-S Diagram
- 19. Case 3: Sub cooling or undercooling
- 20. Case 4: superheated vapour before compression
- 21. Have a good day Thank you